This invention relates to a method and apparatus for processing vegetables, fruits, and produce in general. The operations include storage, cleaning, slicing, cooling, dewatering, and drying of the product for shipment and further commercial use, such as in salads.
The rise of fast food chains and consumers' desire for salads, salad bars and salad ingredients prepared in advance have required the production of large quantities of individual vegetables, fruits, and the like for shipment to particular outlets for subsequent commercial preparation. Numerous problems exist in the prior art which result in slow production at the plant, poor appearance and taste of the product, high bacteria count, and poor shelf life because of improper cooling or handling.
One problem resides in the initial cleaning of the vegetables. Typical prior art devices use brush washers that can bruise the vegetables, which in turn allows water to bleed out. This results in poor appearance and shelf life.
Slow production can occur from a clogged slicer. This situation can arise, for example, when a trimming table is improperly controlled so that an excess quantity of vegetables reaches the slicer at one instant. Alternatively, improperly trimmed vegetables can require an inordinate amount of sorting at the packing step of the operation.
Once the vegetables are sliced, they must be cooled and dried for packing. Existing methods of accomplishing this include pumping the vegetables with chilled, chlorinated water, in a slurry through a long pipe until the vegetables have had an adequate dwell time to achieve the proper cooling and chlorination treatment. The pressure from the pumping frequently damages the vegetables, especially delicate ones such as thin cucumber slices. The pumping often blows out seed sacks of the cucumbers, resulting in either diminished quality of the shipped product or additional labor costs in inspecting and removing the damaged product before packing.
Another method of cooling and cleaning involves running the vegetables through an open flume. Typically the dwell time in these flumes is not adequate to chill the vegetables, a step necessary to help properly kill bacteria. Also, as the vegetables are lifted from the flume they pass through a top layer of dirt, bacteria, and scum that accumulates at the surface of the water. Thus, undesirable germs and particles can adhere to the vegetables as they are transported through the process.
Current drying devices are large, basket-type centrifuges that force the water through the outer screens of the basket as the centrifuge spins. The centrifugal force necessary to cast water from the surface of the product also damages interior cells. The additional water lost by the damaged cells from the centrifuge process often results in a product with a limp appearance and texture, characteristics which are undesirable to the end user. The loss of water can also result in a less palatable product.
Yet another problem in processing vegetables results from the ambient air temperature in which the processing occurs. Despite the use of chilled water or other means to cool the products, frequently the final temperature of the processed and packed product is undesirably high, further effecting the appearance and shelf life of the shipped product.
Another problem is the chill damage that can occur to vegetables during initial storage. For example, a supplier may prepare and sell cucumbers, peppers, and radishes to a distributor. Cucumbers and green peppers have an optimum storage temperature of about 45 degrees, approximately ten degrees warmer than radishes. The undesirable alternatives for storage require either an improper storage temperature for certain items or two separate storage and refrigeration mechanisms.